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Related papers: The pion-nucleon sigma term from Lattice QCD

200 papers

The RQCD collaboration proposed a projection method to remove the excited state contamination in lattice OCD calculations of nuclear form factors. The effectiveness of this method in removing the two-particle nucleon-pion-state…

High Energy Physics - Lattice · Physics 2020-02-28 Oliver Bar

We calculate the electric dipole moment of the nucleon induced by the QCD theta term. We use the gradient flow to define the topological charge and use $N_f = 2+1$ flavors of dynamical quarks corresponding to pion masses of $700$, $570$,…

High Energy Physics - Lattice · Physics 2021-01-27 Jack Dragos , Thomas Luu , Andrea Shindler , Jordy de Vries , Ahmed Yousif

We present results on the light, strange and charm nucleon scalar and tensor charges from lattice QCD, using simulations with $N_f=2$ flavors of twisted mass Clover-improved fermions with a physical value of the pion mass. Both connected…

We employ chiral perturbation theory to calculate the nucleon-pion-state contribution to the 3-point correlation functions measured in lattice QCD to compute various moments of parton distribution functions (quark momentum fraction,…

High Energy Physics - Lattice · Physics 2017-03-08 Oliver Bar

The effects of the CP violating $\theta$ term in the QCD Lagrangian upon low energy hadronic phenomenology are reconsidered. Strong CP violating interactions among Goldstone bosons and octet baryons are incorporated into an effective chiral…

High Energy Physics - Phenomenology · Physics 2010-11-01 Peter Cho

The experimental search for CP violation in paramagnetic atomic and molecular systems has made impressive progress in recent years. This has led to strong upper limits on the electron electric dipole moment. The same measurements can also…

High Energy Physics - Phenomenology · Physics 2025-10-24 Heleen Mulder , Rob Timmermans , Jordy de Vries

Partially quenched Quantum Chromodynamics with Wilson fermions on a lattice is considered in the framework of chiral perturbation theory. Two degenerate quark flavours are associated with a chirally twisted mass term. The pion masses and…

High Energy Physics - Lattice · Physics 2010-12-17 Gernot Münster , Christian Schmidt , Enno E. Scholz

A new formalism to calculate the in-medium chiral condensate is presented. At lower densities, this approach leads to a linear expression. If we demand a compatibility with the famous model-independent result, then the pion-nucleon sigma…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. X. Peng , M. Loewe , U. Lombardo , X. J. Wen

We perform a detailed, fully-correlated study of the chiral behavior of the pion mass and decay constant, based on 2+1 flavor lattice QCD simulations. These calculations are implemented using tree-level, O(a)-improved Wilson fermions, at…

Previous lattice QCD calculations of axial vector and pseudoscalar form factors show significant deviation from the partially conserved axial current (PCAC) relation between them. Since the original correlation functions satisfy PCAC, the…

High Energy Physics - Lattice · Physics 2020-02-26 Yong-Chull Jang , Rajan Gupta , Boram Yoon , Tanmoy Bhattacharya

We employ leading order covariant chiral perturbation theory to compute the nucleon-pion-state contribution to the 3-point correlation functions one typically measures in lattice QCD to extract the isovector nucleon charges $g_A,g_T$ and…

High Energy Physics - Lattice · Physics 2016-09-21 Oliver Bar

We investigate the possibility to determine the value of the pion-nucleon sigma term $\sigma_{\pi N}$ precisely by the experimental observables of the deeply bound pionic atoms. We discuss the sensitivity of the observables to $\sigma_{\pi…

Baryon chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom is considered. Using the extended on-mass-shell renormalization scheme, a manifestly Lorentz-invariant effective field theory with a systematic power counting…

High Energy Physics - Phenomenology · Physics 2009-11-11 C. Hacker , N. Wies , J. Gegelia , S. Scherer

A study of the chiral behavior of pseudoscalar masses and decay constants is carried out in quenched lattice QCD with Wilson fermions. Using the modified quenched approximation (MQA) to cure the exceptional configuration problem, accurate…

High Energy Physics - Lattice · Physics 2009-10-31 W. Bardeen , A. Duncan , E. Eichten , H. Thacker

Nucleon electric dipole moments originating from strong CP-violation are being calculated by several groups using lattice QCD. We revisit the finite volume corrections to the CP-odd nucleon matrix elements of the electromagnetic current,…

High Energy Physics - Phenomenology · Physics 2014-07-25 Tarik Akan , Feng-Kun Guo , Ulf-G. Meißner

Heavy baryon chiral perturbation theory ($\chi$PT), where the $\Delta$ resonance is included, is used in order to examine the axial charged-current component of the weak interaction process at low neutrino energies. At leading chiral order…

Nuclear Theory · Physics 2019-03-13 Fred Myhrer

We present an extraction of the pion-nucleon ($\pi N$) scattering lengths from low-energy $\pi N$ scattering, by fitting a representation based on Roy-Steiner equations to the low-energy data base. We show that the resulting values confirm…

High Energy Physics - Phenomenology · Physics 2018-01-17 Jacobo Ruiz de Elvira , Martin Hoferichter , Bastian Kubis , Ulf-G. Meißner

A chiral-perturbative consideration of the near-threshold pp -> pp pi0 reaction indicates that the pion-rescattering term has a substantial energy and momentum dependence. The existing calculations that incorporate this dependence give pion…

Nuclear Theory · Physics 2008-11-26 T. Sato , T. -S. H. Lee , F. Myhrer , K. Kubodera

Recent results on pion physics from lattice QCD are reviewed. We discuss quark mass dependences of pion mass and decay constant and compare them with the predictions from chiral perturbation theory. In particular we focus on the convergence…

High Energy Physics - Lattice · Physics 2014-11-20 Sinya Aoki

The study of excited hadron spectra using Lattice QCD is currently evolving. An important step toward obtaining resonance parameters from Lattice QCD is the calculation of finite volume energy spectra. Somewhat more rigorous studies of…

High Energy Physics - Lattice · Physics 2011-12-07 John Bulava